The present invention relates to a hair dye composition having markedly high dyeing power, can strongly impart the hair with an extremely vivid color ranging from greenish yellow, yellow, red to blue, has less color fade over time and undergoes a small change in the color tone of the dye even after storage.
Hair dyes can be classified by the dye to be used therefor, or whether they have bleaching action of melanin or not. Typical examples include a two-part permanent hair dye composed of a first part containing an alkali agent, an oxidation dye and a direct dye such as nitro dye and a second part containing an oxidizing agent; and one-part semi-permanent hair dye containing an organic acid or an alkali agent, and a direct dye such as acid dye, basic dye or nitro dye.
The above-described permanent hair dye is however accompanied with the drawbacks that color tone imparted by an oxidation dye is not so vivid and the color of the hair dyed with a vivid-color producing nitro dye ordinarily employed as a direct dye markedly fades over time and becomes dull soon even if the color tone rightly after dyeing is very vivid (Japanese Patent Application Laid-Open (Kokai) No. Hei 6-271435).
Recently, hair dyes containing as a direct dye a so-called cationic dye having a cation group contained in their conjugate system have been reported (Japanese Language Laid-Open Publication (PCT) No. Hei 8-507545, 8-501322 or 10-502946, or Japanese Patent Application Laid-Open (Kokai) No. Hei 10-194942). They have been found to involve drawbacks that intended dyeing effects are not available owing to decomposition of them caused by mixing, upon hair dyeing, with hydrogen peroxide ordinarily employed as an oxidizing agent; and that when a cationic group is contained in an azo-based (xe2x80x94Nxe2x95x90Nxe2x80x94) conjugated system, they are unstable to an alkali agent or a reducing agent essentially contained in a permanent hair dye.
An object of the present invention is to provide a hair dye composition having high hair dyeing power, less color fade over time, and excellent storage stability to permit only a smaller change in color tone of the dye after storage.
The present inventors have found that use of the below-described compoundxe2x80x94which is known in Japanese Patent Applications Laid-Open (Kokai) Nos. Sho 49-87730, 53-139634, 51-136723 and 55-99955 as a cationic dye for dyeing or printing therewith synthetic resins, synthetic fibers, paper or leatherxe2x80x94as a hair dye, the resulting hair dye composition can strongly impart the hair with an extremely vivid color ranging from greenish yellow, yellow, red to blue without decomposing the dye upon hair dyeing, exhibits excellent light resistance, washing resistance, perspiration resistance, friction resistance and heat resistance, and undergoes a small change in the color tone of the dye after storage as compared with that rightly after preparation because the dye exists in the composition stably.
In one aspect of the present invention, there is thus provided a hair dye composition comprising, as a direct dye, a compound represented by the following formula (1): 
wherein, ring A represents a benzene ring which may have a substituent or may further be cyclocondensed with another aromatic ring;
B represents an aryl group which may have a substituent or may be coupled with R2 to form a heterocyclic structure which will be described later, or a heterocyclic group which may have a substituent or may be coupled with R2 to form a heterocyclic structure which will be described later,
D represents a nitrogen atom or a group CR4 (in which R4 represents a hydrogen atom or a C1-6 alkyl group);
E represents a group NR5, CR6R7 or CR6xe2x95x90CR7 (in which R5 represents a C1-6 alkyl group which may have a substituent, a C2-6 alkenyl group which may have a substituent or an aryl group which may have a substituent, or forms, when taken together with R2, a ring which will be described later, and R6 and R7 each independently represents a hydrogen atom or a C1-6 alkyl group), an oxygen atom or a sulfur atom;
R1 represents a C1-6 alkyl group which may have a substituent, a C2-6 alkenyl group which may have a substituent or an aryl group which may have a substituent;
R2 represents a divalent group bonded to B or forms, when taken together with R3 or R5, a ring which will be described later,
R3 forms, when taken together with R2, a ring which will be described later;
n stands for 0 or 1, with the proviso that when n=0, R2 and R5, when taken together with Nxe2x80x94Cxe2x80x94C, form a 5- to 7-membered nitrogen-containing heterocyclic structure which may have a substituent, or R2 is bonded to B, thereby forming a 6- or 7-membered heterocyclic structure which may have a substituent and may contain a hetero atom other than D and when n=1, R2 and R3, when taken together with Cxe2x95x90Dxe2x80x94N, form a 5- to 7-membered nitrogen-containing heterocyclic structure which may have a substituent, and
Xxe2x88x92 represents an anion.
In another aspect of the present invention, there is also provided a method for dyeing the hair with the above-described hair dye composition.
In the formula (1), examples of the substituent which the ring A may have include alkyl groups, aryl groups, alkoxy groups, amino group, hydroxy group, cyano group, nitro group and halogen atoms, more specifically, methyl group, ethyl group, methoxy group, ethoxy group, chlorine atom and bromine atom. Examples of the aromatic ring with which the ring A may be cyclocondensed include a benzene ring.
Examples of the aryl group represented by B include phenyl, 1-naphthyl and 2-naphthyl groups, while those of the heterocyclic group include 2-benzthiazolyl and 3-indolyl groups, each of which may be substituted with a chlorine atom, bromine atom, nitro group, cyano group, C1-4 alkyl group, phenyl group, benzyl group, C1-4 alkoxy group, hydroxy group, phenoxy group, benzyloxy group, C1-4 alkylsulfonyl group, phenylsulfonyl group, benzylsulfonyl group, aminocarbonyl group, mono- or di-(C1-4 alkyl)aminocarbonyl group, aminosulfonyl group, C1-4 alkylcarbonyl group, C1-4 alkylcarbonylamino group, benzoylamino group, phenylazo group, and a group NR8R9 (in which R8 and R9 each independently represents a hydrogen atom, C1-4 alkyl group, aryl group, aralkyl group, unsubstituted or mono- or di-(C1-4 alkyl)-substituted amino(C1-4 alkyl) group, amino(C1-4 alkyl) group substituted by a group of the formula (1) from which one hydrogen atom has been removed, or (C1-4 alkoxy) (C1-4 alkyl)amino group). The number of these substituents is 1 to 3. The cycle-constituting atom may be coupled with the above-exemplified substituent to form another cyclic structure.
Examples of the C1-6 alkyl group represented by R4 in the case where D represents a group CR4 or by R6 or R7 in the case where E represents a group CR6R7 or CR6xe2x95x90CR7 include methyl, ethyl, propyl, isopropyl and cyclohexyl groups. Preferred examples of R4, R6 or R7 include hydrogen atom and methyl groups.
Examples of the C1-6 alkyl group represented by R5 in the case where E represents a group NR5 include methyl, ethyl, propyl, isopropyl and cyclohexyl groups; those of the C2-6 alkenyl group include ethenyl and propenyl groups; and those of the aryl include phenyl and naphthyl groups, each of which may be substituted with an aryl, alkoxy, amino, hydroxy or cyano group, or a halogen atom.
Examples of the C1-6 alkyl group represented by R1 include methyl, ethyl, propyl, isopropyl and cyclohexyl groups, those of the C2-6 alkenyl group include ethenyl and propenyl groups, and those of the aryl group include phenyl and naphthyl groups, of which the alkyl group is preferred as R1. Examples of the group which may be a substituent for them include aryl groups, cyano group, halogen atoms, hydroxy group, C1-4 alkoxy groups, NR10R11 (in which R10 and R11 each independently represents a hydrogen atom, C1-4 alkyl group, aryl group, aralkyl group, unsubstituted or mono- or di(C1-4 alkyl)substituted amino(C1-4 alkyl) group, or (C1-4 alkoxy) (C1-4 alkyl)amino group) and a group of the formula (1) from which one hydrogen atom has been removed.
Examples of the R5-R2 or R2-R3 in the case where a 5- to 7-membered nitrogen-containing heterocyclic structure which may have a substituent is formed by R2 and R5 when they are taken together with Nxe2x80x94Cxe2x80x94C at n=0, or by R2 and R3 when taken together with Cxe2x95x90Dxe2x80x94N at n=1, include groups represented by xe2x80x94(CR12R13)mxe2x80x94(in which R12 and R13 each independently represents a C1-4 alkyl group and m stands for an integer of 2 to 4).
Examples of the divalent group, as R2, bonded to B in the case where a 6- or 7-membered heterocyclic structure which may have a substituent and may have a hetero atom other than D is formed by bonding of R2 to B when n=0 include groups xe2x80x94CHxe2x95x90Nxe2x80x94 and xe2x80x94COxe2x80x94Oxe2x80x94.
Examples of the anion represented by Xxe2x88x92 include chloride ions, bromide ions, iodide ions, trichlorozincic acid ions, tetrachlorozincic acid ions, sulfuric acid ions, hydrosulfuric acid ions, methyl sulfate ions, phosphoric acid ions, formic acid ions and acetic acid ions.
Specific examples of the direct dye (1) to be used in the present invention will next be shown. 
At least one of these direct dyes (1) can be used or they may be used in combination with another direct dye. In particular, when the direct dye (1) is a yellow dye, combination with red and blue dyes makes it possible to dye the hair with a deep and highly lustrous dark brown or black color.
Examples of the direct dye other than the direct dyes (1) include Basic Blue 7 (C. I. 42595), Basic Blue 26 (C. I. 44045), Basic Blue 99 (C. I. 56059), Basic Violet 10 (C. I. 45170), Basic Violet 14 (C. I. 42515), Basic Brown 16 (C. I. 12250), Basic Brown 17 (C. I. 12251), Basic Red 2 (C. I. 50240), Basic Red 22 (C. I. 11055), Basic Red 76 (C. I. 12245), Basic Red 118 (C. I. 12251:1) and Basic Yellow 57 (C. I. 12719); and basic dyes as described in Japanese Patent Publication No. Sho 58-2204, Japanese Patent Application Laid-Open (kokai) No. Hei 9-118832, Japanese Language Laid-Open Publication (PCT) No. Hei 8-501322 or Japanese Language Laid-Open Publication (PCT) No. Hei 8-507545.
The direct dye (1) is preferably added in an amount of 0.01 to 20 wt. %, more preferably 0.05 to 10 wt. %, especially 0.1 to 5 wt. % based on the whole composition (after mixture of all the component parts when the composition is a two part or three part composition; this will apply equally hereinafter). When another direct dye is added in combination, the content of it in total with the direct dye (1) preferably ranges from 0.05 to 10 wt. %, especially 0.1 to 5 wt. %.
The hair dye composition of the present invention is preferably adjusted to pH 6 to 11, with pH 8 to 11 being especially preferred. Examples of the alkali agent to be used for pH adjustment include ordinarily employed ones such as ammonia, organic amines and salts thereof. The alkali agent is preferably added in an amount of 0.01 to 20 wt. %, more preferably 0.1 to 10 wt. %, especially 0.5 to 5 wt. % based on the whole composition.
In the hair dye composition of the present invention, an oxidizing agent can be incorporated. In this case, hair dyeing and bleaching can be carried out simultaneously, which facilitates more vivid hair dyeing. Ordinarily employed oxidizing agents, for example, hydrogen peroxide, persulfates such as ammonium persulfate, potassium persulfate and sodium persulfate, perborates such as sodium perborate, percarbonates such as sodium percarbonate and bromates such as sodium bromate and potassium bromate are usable. Out of them, hydrogen peroxide is especially preferred. The oxidizing agent is added in an amount of 0.5 to 10 wt. %, especially 1 to 8 wt. %, based on the whole composition.
In the hair dye composition of the present invention, an oxidation dye can be incorporated further. This incorporation enables markedly vivid dyeing not attainable by the single use of an oxidation dye. The above-exemplified oxidizing agents can be used as an oxidizing agent, with hydrogen peroxide being particularly preferred. Alternatively, an oxidizing enzyme such as laccase can be employed. For the oxidation dye, known color developers and couplers ordinarily employed for an oxidation type hair dye can be used.
Examples of the developer include p-phenylenediamines having one or several groups selected from NH2xe2x80x94, NHRxe2x80x94 and NR2-groups (in which R represents a C1-4 alkyl or hydroxyalkyl group) such as p-phenylenediamine, p-toluylenediamine, N-methyl-p-phenylenediamine, chloro-p-phenylenediamine, 2-(2xe2x80x2-hydroxyethylamino)-5-aminotoluene, N,N-bis-(2-hydroxyethyl)-p-phenylenediamine, 2-hydroxyethyl-p-phenylenediamine, 2,6-dimethyl-p-phenylenediamine, methoxy-p-phenylenediamine, 2,6-dichloro-p-phenylenediamine, 2-chloro-6-methyl-p-phenylenediamine, 6-methoxy-3-methyl-p-phenylenediamine, 2,5-diaminoanisole, N-(2-hydroxypropyl)-p-phenylenediamine and N-2-methoxyethyl-p-phenylenediamine; 2,5-diaminopyridine derivatives and 4,5-diaminopyrazole derivatives; p-aminophenols such as p-aminophenol, 2-methyl-4-aminophenol, N-methyl-p-aminophenol, 3-methyl-4-aminophenol, 2,6-dimethyl-4-aminophenol, 3,5-dimethyl-4-aminophenol, 2,3-dimethyl-4-aminophenol and 2,5-dimethyl-4-aminophenol; o-aminophenols, o-phenylenediamines, 4,4xe2x80x2-diaminophenylamine and hydroxypropyl-bis(N-hydroxyethyl-p-phenylenediamine); and salts thereof.
Examples of the coupler include 1-naphthol, 1,5-dihydroxynaphthalene, 1,7-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 5-amino-2-methylphenol, 5-(2xe2x80x2-hydroxyethylamino)-2-methylphenol, 2,4-diaminoanisole, m-toluylenediamine, resorcin, m-phenylenediamine, m-aminophenol, 4-chlororesorcin, 2-methylresorcin, 2,4-diaminophenoxyethanol, 2,6-diaminopyridine, 2-amino-3-hydroxypyridine, 4-hydroxyindole, 6-hydroxyindole, 2,4-diamino-6-hydroxypyrimidine, 2,4,6-triaminopyrimidine, 2-amino-4,6-dihydroxypyrimidine, 4-amino-2,6-dihydroxypyrimidine, 4,6-diamino-2-hydroxypyrimidine and 1,3-bis(2,4-diaminophenoxy)propane; and salts thereof.
At least one of the above-exemplified ones as each of the developer and coupler can be used. The content of each of the developer and coupler is preferably 0.01 to 20 wt. %, especially 0.5 to 10 wt. % based on the whole composition.
To the hair dye composition of the present invention, a known autoxidation dye typified by an indole or an indoline, or a known direct dye such as a nitro dye or a disperse dye can also be added.
When an anionic component (such as anionic surfactant or anionic polymer) is added to the hair dye composition of the present invention, it is preferred to satisfy the following equation:
xe2x80x9cIon activity concentration of the anionic component/ion activity concentration of the cationic direct dye (1)xe2x89xa68xe2x80x9d
The term xe2x80x9cion activity concentrationxe2x80x9d as used herein means xe2x80x9cmolar concentrationxc3x97ionic valencexe2x80x9d.
Addition of a polyol, polyol alkyl ether, cationic or amphoteric polymer or silicone to the hair dye composition of the present invention is preferred, because the resulting composition can dye the hair uniformly and has improved cosmetic effects of the hair.
In addition to the above-described components, those ordinarily employed as a raw material for cosmetics can be added to the hair dye composition of the present invention. Examples of such an optional component include hydrocarbons, animal or vegetable fats and oils, higher fatty acids, organic solvents, penetration promoters, cationic surfactants, natural or synthetic polymers, higher alcohols, ethers, amphoteric surfactants, nonionic surfactants, protein derivatives, amino acids, antiseptics, chelating agents, stabilizing agents, antioxidants, plant extracts, crude drug extracts, vitamins, colorants, perfumes and ultraviolet absorbers.
The hair dye composition of the present invention can be prepared in a conventional manner into a one-part composition, a two-part composition having a first component part containing an alkali agent and a second component part containing an oxidizing agent, or a three-part composition having, in addition to these two component parts, a powdery oxidizing agent such as persulfate. The direct dye (1) can be incorporated in either one or both of these component parts of the two-part or three-part composition. When the hair dye composition of the present invention is one-part type, it is applied to the hair directly, while the two- or three-part type is applied to the hair after mixing these parts upon hair dyeing.
No particular limitation is imposed on the form of the hair dye composition of the present invention. Examples include powder, transparent liquid, emulsion, cream, gel, paste, aerosol, and aerosol foam. It preferably has a viscosity of 2000 to 100000 mPaxc2x7s in the stage of application to the hair (after mixing of all the component parts when the composition is a two-part or three-part type).